Joint implants are well known in the art. For example, one of the most common types of joint prosthetic devices is a knee implant including a femoral component and a tibial component. Other common joint implants are associated with, for example, the hip and shoulder, although many other implant locations are contemplate by the present disclosure, including the spine, spinal articulations, intervertebral discs, facet joints, shoulder joints, elbows, wrists, hands, finger joints, ankles, wrists, feet and toe joints.
The shape and size of various joint implants are becoming increasingly more complex and may include, for example, one or more concavities and/or convexities, as described in various literature, including U.S. patent application Ser. No. 10/997,407, filed on Nov. 24, 2004, the disclosure of which is incorporated by reference herein. Traditional implant manufacturing processes, which may even include manual steps, and which may be satisfactory for less complex shaping, are becoming inadequate. Traditionally, a diseased, injured or defective joint, such as, for example, a joint exhibiting osteoarthritis, would be repaired using standard off-the-shelf implants and other surgical devices. The drawback to this approach is that typically a decision must be made between devices that are either too large or too small or otherwise just not the right shape for the patient's anatomy. In order to make one of these sub-optimal devices fit properly, a surgeon must typically remove an undesirable or unacceptable amount of healthy or undamaged tissue from the surgical site, or accept using an implant that is not optimally sized or capable of being well positioned for the patient—settling for an implant and surgery that is “good enough” in the surgeon's estimation.
Furthermore, joint implants, such as a knee implant that includes tibial and femoral components, often require a relatively large cut on, for example, the tibia. This is due, in part, to satisfy a desired minimum thickness (for strength and/or reliability) of the materials of the component, such as polyurethane for a portion of a tibial component. The cut on the tibia, upon which the tibial component rests, provides space for the desired thickness of the polyurethane tibial component, desirably without overstuffing the joint. Such cuts can often be highly invasive, resulting in loss of valuable bone stock, and over time, osteolysis frequently leads to loosening of the prosthesis. Further, the area where the implant and the bone mate will typically degrade over sufficient time and loading cycles, requiring that the prosthesis be replaced. Since the patient's bone stock is limited, the number of possible replacement surgeries is also limited to a generally finite number of joint arthroplasties.
There are now various custom-made, patient-specific orthopedic implants known in the art, and such implants can be developed using software modeling programs. Such patient-specific implants, such as the iForma®, iUni® and iDuo® (commercially available from ConforMIS, Inc., Burlington, Mass.), offer advantages over the traditional “several-sizes-fit-all” approach such as a better fit, more natural movement, reduction in the amount of bone removed during surgery and a less invasive procedure. Such patient-specific implants generally can be created from images of the patient's joint and/or surrounding anatomical structures. Based on the images, the patient-specific implant can be created both to include surfaces that match existing surfaces in the joint, as well as to include surfaces that approximate an ideal and/or healthy surface that may not exist in the patient prior to any procedure. However, this patient-specific, tailor-made approach can be costly, both in terms of money and time. There remains a need in the art, therefore, for systems and methods of designing, manufacturing and implanting implants, including custom-made or modular implants as well as custom, patient-specific implants, in a more timely and cost effective manner.